The pcre_compile2 function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code and cause a denial of service (out-of-bounds read) via regular expression with a group containing both a forward referencing subroutine call and a recursive back reference, as demonstrated by “((?+1)(1))/”.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-2326
Reference (s):
- https://www.pcre.org/original/changelog.txt
- http://lists.opensuse.org/opensuse-updates/2015-05/msg00014.html
- https://bugs.exim.org/show_bug.cgi?id=1592
- https://fortiguard.com/zeroday/FG-VD-15-016